When Maud Pie was commissioned to perform a geological survey of the stone underlying the Castle of the Two Sisters, she expected to face Timberwolves, hangry coworkers, and lots of silica-rich minerals. But when she stumbles upon a portal buried under the rubble of Celestia and Luna's ancient conflict, she learns that their roles very easily could have been reversed. With nothing but a small pet rock and her trusty core sampling drill, Maud finds herself thrust into a world where magic is useless, water is worth its weight in gold, and survival is far from guaranteed. When every morning brings a Red Dawn, can one pony make a difference?